1. Field of the Invention
The present invention relates generally to periodontics and more particularly it relates to a periodontal probe instrument used to measure the depth of the gingival sulcus and periodontal pockets.
2. Description of the Prior Art
Chronic periodontal disease is an inflammatory disease typically induced by plaque formation. As a result of progressive bone loss around the teeth as a consequence of the disease, the increased sulcus depths in the gums create periodontal pockets. These pockets are indicative of the progression of the disease. To diagnose and treat periodontal disease adequately, it is necessary to monitor the current activity of the disease as well as to evaluate past periodontal destruction. To do that requires that the depths of the gingival sulcus and any periodontal pockets that exist be determined accurately.
Pocket depths are now commonly measured by a periodontal probe that has a thin metal tip that is scored with calibration marks. The probe is inserted into the sulcus between a tooth and the gingiva and advanced until resistance is felt, which indicates that the bottom of the pocket has been reached. A depth reading is then obtained by observing visually the calibration mark that is closest to the top of the gingival margin. Six depth readings are taken around each tooth at prescribed locations, as standard practice. Each of the six readings is recorded. Frequently this recording is done by verbal reporting of the depth to an assistant, who writes it by hand on a dental chart.
Clearly, the use of such a conventional periodontal probe is a time-consuming and hence expensive procedure. Moreover, the depths of the periodontal pockets recorded during such a procedure are not always very accurate. Human error results from the need to interpolate between the calibration marks on the probe, as well as from variations in the pressure of the probe against the bottom of the periodontal pocket at the instant that the depth reading is taken. Additional error sometimes arises from the verbal communciation of the measured values and the manual writing of those values on the record.
A patent search produced the following seven patents in which a periodontal probe with a depth measurement structure is disclosed:
______________________________________ U.S. Pat. No. Dated Patentee ______________________________________ 3,058,225 Oct. 16, 1962 Ward 3,943,914 Mar. 16, 1976 Grenfell et al. 4,250,895 Feb. 17, 1981 Lees 4,340,069 Jul. 20, 1982 Yeaple 4,665,621 May 19, 1987 Ackerman et al. 4,677,756 Jul. 7, 1987 Simon et al. 4,708,647 Nov. 24, 1987 Pippin et al. ______________________________________
Independently, references to periodntal probes were located in U.S. Pat. No. 4,203,223 issued May 20, 1980 to Lautenschlager et al. and a paper entitled "Computerized Periodontal Probe with Adjustable Pressure", written by E. Sild et al., which was published on pp. 53-62 of The International Journal of Periodontics and Restorative Dentistry for April, 1987.